Lammers, Kristin. Infrared spectral and statistical analysis of leaf litter decomposition from the New Jersey Pine Barrens. Retrieved from https://doi.org/doi:10.7282/T3H132C0
DescriptionThe soil of the New Jersey Pine Barrens is developed from porous, sandy and acidic deposits. The cycling of mineral nutrients and leaf litter decomposition within this low nutrient environment is important for sustained forest growth. Periodic disturbances through fire can be an important influence on the cycling of nutrients within the ecosystem. The control burns release mineral nutrients, but the changes in the organic composition of leaf litter and soil humus need to be characterized. Fourier-transform infrared spectroscopy (FT-IR) was used to compare the chemistry and chemical changes in composition of leaf litters before and after a fire. Principal component analysis (PCA) of the presence/absence of vibrational modes in addition to differentiated IR spectra revealed changes in the carbohydrate chemistry of leaf litter at each temperature. Analysis of the identical IR data using numerical values gave supplementary and complementary data to the original binary presence and absence.
Evolved gas analysis (EGA) was applied to each litter species using Thermal Gravimetric Analysis (TGA-IR) to further characterize the changes induced by heating. EGA indicated that CH, CO2 and CO along with other IR regions of gases evolved while heating from ~225 degrees C to ~600 degrees C. Time series ANOVA verifies different weight loss steps in the IR gaseous regions. FT-IR microspectroscopy highlighted differences between the adaxial and abaxial sides of leaves as well as between undisturbed and decomposed leaves.